Repugnant Conclusion and Expected Misery Argument - Killing Happy Animals: Explorations in Utilitarian Ethics - page 117

Conclusion on the deontic level. The Prior Existence View can accept
that only the expected effects on the welfare of the (possible) parents -
and on other already existing persons - determine whether or not to
bring a potential child into existence.
Yet, exactly this alleged advantage has an implication that has been
considered problematic. The Prior Existence View does not take into
account the possible welfare of contingent beings. That a contingent child
would be happy is no reason for having it. But then, is the knowledge that
a contingent child would have a miserable life not a moral reason against
having it either? The point is that the Prior Existence View cannot say this
without inconsistency. This problem has famously been evoked by Parfit's
Case of the Wretched Child. Parfit describes this case as follows:
The Wretched Child : Some woman knows that, if she has a child, he
will be so multiply diseased that his life will be worse than nothing.
He will never develop, will live for only a few years, and will suffer
pain that cannot be wholly relieved. 27
The idea is that in this case, we would surely want to take into account
the expected welfare of the child, which would be negative, as a reason
against causing this child to exist. According to the Prior Existence View,
only actually existing beings should be taken into account in moral
considerations, along with beings that will definitely exist . The problem
is that once this child exists, the choice not to cause it to exist is not
open anymore. And when the couple chooses beforehand not to cause
this child to exist, the potential child is not a child that will definitely
exist. So, the Prior Existence View lacks any basis on which the potential
child's welfare can be taken into account.
If a couple knows before conception that any child that it could have
would (due to a genetic deficiency, say) have a short and very miserable
life, then supposedly most people are inclined to think that the couple is
blameworthy if they have this child. This is brought forward as an attack
against the Prior Existence View. It cannot account for the idea that there
is something morally wrong with having this child. Maybe not every-
body shares this intuition. At least it is playing a prominent role in the
evaluation of the Prior Existence View. Therefore, I will address it here. 28
Either adherents of the Prior Existence View cannot accommodate the
idea that the expected misery for a child should count as a reason against
bringing it into existence. Or, they need to justify that the misery of a
potential miserable child counts in decisions about whether or not to
bring it into existence, while the happiness of a potential happy child